On Wednesday, October 14, 2015 at 11:34:52 AM UTC-4, Randy Yates wrote:
writes:
On Wednesday, October 14, 2015 at 8:55:19 AM UTC-4, None wrote:
"Randy Yates" wrote in message
A transformation T is linear iff
T(a*x1 + b*x2) = a*T(x1) + b*T(x2)
So let's consider a very simple limiter that does this:
L(x) = x, |x| 1
L(x) = sgn(x) * 1, |x| = 1.
Is this linear by the definition above? Nope. Here's
a simple counterexample.
Hi Randy,
agreed, except that what is described above I would call a clipper, not a limiter...
If it alters the envelope AND the waveform, its a clipper.
If it alters only the envelope and NOT the waveform, its a limiter, compressor or AGC.
Mark
Hi Mark,
Define envelope. Define waveform.
--
Randy Yates
Digital Signal Labs
http://www.digitalsignallabs.com
see
https://en.wikipedia.org/wiki/Envelope_(waves)
Blue is the waveform
red and green are the envelopes which for audio work are almost always the inverse of each other
or see Richard Lyons's book page 366 in the 2nd edition
he defines it mathematically as the abs value of the complex analytical signal
which = sqrt of real part squared + imaginary part squared